An analysis of remote sensing land subsidence data in the Netherlands

Land subsidence is a major challenge in many parts of the Netherlands, and in order to develop practically plausible scenarios and pathways of possible mitigation and adaptation measures under inclusive governance, it is necessary to study and analyse historical land subsidence data in the Netherlands.

This study leverages the estimated ground-surface displacement amount from "Bodemdalingskaart.nl" based on remote sensing data from Sentinel-1 processed data every twelve days for five consecutive years from October 2017 to October 2022. The main goal of this study is to identify places that have significant land subsidence values, which is a critical stage in determining which and where mitigation and adaptation measures might be implemented.

More than 4 million land subsidence scatterer points throughout the whole Netherlands were analysed to identify locations with high subsidence values, and the results were then interpolated with administrative and elevation maps of the Netherlands, allowing for the extraction of high-resolution data that provides detailed insights into land subsidence patterns across the entire Netherlands. In total, 155 locations were recognized as having significant land subsidence values; in our analysis, the significant value was set as 3 mm/year. The 155 identified locations were distributed among all twelve provinces. Moreover, 60 of the 155 locations were located in areas below sea level, mainly in the six western provinces from Groningen in the north to Zeeland in the south, indicating a high risk of flooding in these places in the future if relative sea level rise (RSLR) is taken into consideration.

The identified places that exhibit significant land subsidence values should be subjected in the next stage to further assessment and evaluation through 3D modelling,  damage assessment, and Social Cost Benefit Analysis (SCBA) to allow the stakeholders to effectively prioritize all possible mitigation and adaptation measures through an appropriate governance framework. By pinpointing the specific locations where land subsidence has relatively significant values, different scenarios and pathways for different mitigation and adaptation measures could be developed to address the adverse effects of land subsidence on all affected parties in the Netherlands, both in urban and rural areas.

In summary, this study uses the extensive land subsidence point data supplied by "Bodemdalingskaart.nl" to investigate the patterns and features of land subsidence across the Netherlands. Leveraging land subsidence point data provided a more meaningful knowledge of the spatial distribution of significant land subsidence values in the Netherlands, allowing for the identification of places where more attention and further investigation are required.